In the medical field, implantable leads are used with a wide variety of medical devices. For example, implantable leads are commonly used to form part of implantable cardiac pacemakers that provide therapeutic stimulation to the heart by delivering pacing, cardioversion or defibrillation pulses via electrodes disposed on the leads. In addition, implantable leads are used in neurological devices such as deep-brain stimulation devices, and spinal cord stimulation devices. Leads are also used with a wide variety of other medical devices including, for example, devices that sense chemical conditions in a patient's blood, and implantable drug or beneficial agent dispensers or pumps. In short, medical leads can be used for sensing purposes, stimulation purposes, drug delivery, and so forth.
Medical leads include a lead body formed of an outer polymeric sheath encasing one or more insulated electrical conductors; the lead body extends from a connector, terminating a proximal end, to a distal end. A distal end of each conductor is coupled to one or more electrodes while a proximal end of each conductor is coupled to a contact of the connector that is in turn coupled to a connector port of an implantable medical device (IMD), which delivers pulses or shocks to a patient via the lead electrodes, or receives sensed signals from the electrodes.
IMDs often include one or more connector ports conforming to one or more connector standards, examples of such standards include the IS-1standard for low voltage electrical coupling and the DF-1 standard for high voltage electrical coupling, both commonly used in implantable cardiac pacemakers and defibrillators. When a lead connector does not conform to a standard, a connector sleeve may be fitted over the lead connector in order to adapt the connector for coupling within a standard connector port of an IMD. In such a system, means to secure or retain the connector sleeve on the lead connector is a desirable feature.